ICL3221, ICL3222, ICL3223, ICL3232, ICL3241, ICL3243

4. Application Information

FN4805 Rev.23.00

Page 21 of 36

Apr.26.19

4.13 Interconnection with 3V and 5V Logic

The ICL32xx directly interface with 5V CMOS and TTL logic families. With the ICL32xx at 3.3V, and the logic

supply at 5V, AC, HC, and CD4000 outputs can drive ICL32xx inputs, but ICL32xx outputs do not reach the

minimum VIH for these logic families. See Table 7 for more information.

Figure 16. Transmitter Loopback Test Circuit

Figure 17. Loopback Test at 120kbps

Figure 18. Loopback Test at 250kbps

Table 7.

Logic Family Compatibility with Various Supply Voltages

System Power-Supply

Voltage (V)

VCC Supply

Voltage (V)

Compatibility

3.3

3.3

Compatible with all CMOS families.

5

5

Compatible with all TTL and CMOS logic families.

5

3.3

Compatible with ACT and HCT CMOS, and with TTL. ICL32xx outputs

are incompatible with AC, HC, and CD4000 CMOS inputs.

ICL32xx

VCC

FORCEOFF

C1

C2

C4

C3

+

+

+

+

1000pF

V+

V-

5k

TIN

ROUT

C1+

C1-

C2+

C2-

RIN

TOUT

+

VCC

0.1µF

VCC

EN

SHDN OR

T1IN

T1OUT

R1OUT

5µs/Div

VCC = +3.3V

5V/Div

C1 - C4 = 0.1µF

T1IN

T1OUT

R1OUT

2µs/Div

5V/Div

VCC = +3.3V

C1 - C4 = 0.1

μF